Study On SNPs Of HSL Gene And Its Relationship With Several Traits In Shaanbei White Cashmere Goat

Hormone-sensitive lipase (HSL) is the key enzyme responsible for the mobilization of lipid. In this experiment, the coding sequence of HSL gene was cloned and its sequence was analyzed for function and genetic varibility study, which will contribute to further study of lipid mobilization mechanism and synthesis channel of fatty acids in mammary gland. Also, HSL gene could be a candidate gene effecting on the growth and development of Shaanbei White Cashmere goat, by analyzing SNPs of HSL gene and its association with some of the traits. Considering above-mentioned reasons, some studies were taken basing on the following aspects: (1) The CDs of HSL gene was cloned by RT-PCR. The putative signal sequences, transmembrane domain, tertiary structure of HSL protein, and homology were predicted by way of bioinformatics.(2) The expression of HSL gene in one lactation stage (early, peak, mid, late, end ,and dry lactation stages) was analyzed by real-time PCR.(3) For studying genetic varibility, exonâ… ,â…¡andâ…§of HSL gene were analyzed by PCR-SSCP and PCR-Sequencing. The results as following:(1) The CDs of HSL gene was gained (EU273879).The o coding sequence of HSL gene was composed of 2271 bp, which encoded a polypeptide of 756 amino acids. The homologies of cDNA nucleotide sequence of HSL gene with the counterparts of bovine (NM₀01080220), human (NM₀05357), and mouse (B021642) were 96 %, 86 % and 79 %, and the homologies of peptide sequence were 96 %, 85 % and 83 %, respectively.(2) The expression profile of HSL gene during the whole lactation period was analyzed by real-time quantitative PCR. The mRNA abundance of HSL gene showed the early to peak lactation stage with whole constant high level followed by significant drop to the lowest lever in mid lactation stage before gradual increase in late, then mild decrease from late to end lactation stages, which reflected the uncorrelation of HSL gene expression to milk yield and secretion of milk fat globule.The function of HSL gene in goat mammary gland should be study for further.(3) The analysis results of the SNPs of HSL gene showed: these locuses of exonâ… ,â…¡andâ…§were at Hardy-Weinberg equilibration in the Shaanbei White Cashmere Goat, their polymorphic information content (PIC) were 0.094 8, 0.114 2 and 0.802 3, which meaned low diversity in exonâ… ,â…¡and moderate diversity in exonâ…§respectively. A mutation, G→A in exonâ… locus which was tested by using PCR-Sequencing method, caused the glycine (G) into Alanine(A), there was very significant difference between the genotype of AB and AA for cashmere productive (P<0.01) and significant difference for the wither height and back-fat thickness (P<0.05), in addition, there was no significant difference for other traits, the trend of"AB>AA"was noted for birth weight, weaning weight, cashmere length, yearling weight, wither height, body length, circumference of cannon and back-fat thickness, the trend of"AA>AB"was observed in the traits of cashmere productive, hair length, heart girth, and loin eye area; A mutation, C→A in exonâ…¡locus which was tested for the first time, but didn't cause amino acid sequence changed, there was very significant difference between the genotype of AB and AA for yearling weight (P<0.01), there was no significant difference for other traits, the trend of"AB>AA"was noted for weaning weight, yearling weight, hair length, wither height, body length, circumference of cannon and back-fat thickness, the trend of"AA>AB"was observed in the traits of hair length, cashmere productive, heart girth, and loin eye area; A mutation, A→G in exonâ…§locus caused the Isoleucine(I)into Valine (V), there was very significant difference between the genotype of AB and AA, AA and BB for loin eye area and back-fat thickness (P<0.05), and significant difference between the genotype of AB and BB for cashmere productive (P<0.05), there was no significant difference for other traits, the trend of"BB>AA>AB"was observed in the traits of birth weight, wither height, body length, hair length and circumference of cannon, the trend of"BB>AB>AA"was observed in the traits of hair length, the trend of"AB>AA>BB"was observed in the traits of back-fat thickness and cashmere productive, the trend of"AA>BB>AB"was observed in the traits of yearling weight and loin eye area, the trend of"AA>AB>BB"was noted for two traits of weaning weight and heart girth.